Load-regulated governing device for fluid-pressure.



J. S. DOY-LE & F. HEDLBY. LoLD REGULATED GUVERNING DEVICE EUR FLUID PRESSURE. APPLICATION FILED AUG. 23, 1912.

1,096,493 Patented May 12, 1914.v

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UTED STATES PATENT OFFICE.

JAMES S. DOYLE, OF MOUNT VERNON, AND FRANK HEDLEY, 0F YONKERS, NEW YORK.

LOAD-REGULATED GOVERNING DEVICE FOR FLUID-PRESSURE.

Specication of Letters Patent.

Patented May 12, 1914.

Application led August 23, 1912. Serial No. 716,657.

To all 'whom it may concern:

Be it known that we, JAMEs S. DoYLn and FRANK HEDLEY, both citizens of the United States, residing, respectively, at Mount Vernon and Yonkers, in the county of Testchester and State of New York, have nvented a certain new and useful Improvement in Load-Regulated Governing Devices for Fluid-Pressure, of which the following is a specification.

This invention relates in general to apparatus for regulating the `fluid pressure for braking purposes upon railway cars according to the weight of the load upon the car, and is more particularly designed for use in connection with electrically propelled vehicles in which the air pressure for the brake system is supplied to a main reservoir by means of an electric motor-driven pump, the motor of which is controlled by an electric pump governor according to the pressure in the reservoir.

It is well known that a higher braking power is required to control a heavily loaded car than a light or empty car, also that a much greater braking pressure may be applied to the shoes of a loaded car than to a light car without danger of sliding the wheels. It is therefore important to be able to vary the maximum braking pressure according to the weight of the load in order that the braking apparatus shall operate efticiently and satisfactory in actual service.

rlhe principal object of our invention is therefore to provide means for automatically varying the maximum degree of pressure stored for braking purposes, in accordance with the weight of the .load on the car, and as a preferred means for this purpose we may employ a device governed by the weight of the load on the car for regulating the pump governor, whereby the maximum degree of reservoir pressure at which the governor cuts out the pump will be increased as the load is increased.

The single figure of the accompanying drawing illustrates diagrammatically an apparatus embodying our improvement.

According to the construction shown, our improvement is applied in connection with an electric pump governor of the type commercially known as the Westinghouse Gr type, in which a magnet coil is employed for assisting the spring to hold the switch closed and thereby require the reservoir pressure to rise to a point suflicient to overcome both the spring and the magnetic pull of the coil in order to open the switch and eut out the pump. Current is supplied to the motordriven pump, 20, through leads, 4, connected to the switch terminal points, 8, one of said leads containing the coil, 2, of the governor. The switch terminal points are adapted to be joined by the connecting bar, 9, when the switch is closed, at which time current lows through leads, Ll, switch terminal points and coil, 2, to the motor-driven pump, 20, which operates to compress air into the reservoir, l. As the pressure accumulates in the reservoir, it is also admitted to cylinder, G, where it acts upon the piston, 5, and rod, 7 of the governor and tends to open the switch against the pressure of the adjustable spring, l2, and the magnetic pull exerted by the coil, Q. lVhen the air pressure has increased to a point sul'licient to overcome the spring and the pull of the magnet, it pushes the switch bar away from the switch terminals, and the instant the circuit, which includes the coil, 2, is broken, the magnetic pull, of course, ceases, so that the governor piston and rod move witha quick positive movement to the cut out position at the end of the stroke of the piston. The spring, 12, is adjusted for the cutting in pressure, and when the reservoir pressure has reduced to the degree for which the spring is set, it operates to move t the switch bar to its closed position, the magnet, 2, being energized the instant that the contact is made. The construction, as thus far described, relates to this standard form of electric pump governor.

According to our improvement,any means controlled by the weight of the load on the car may be employed for regulating the action ofthe pump governor, and the pressure in the reservoir. As a preferred construction we have shown an additional coil, 3, for the governor, included in a circuit, 14, and acting in a manner similar to the coil, 2, that is, to exert a magnetic pull upon the armature or switch bar, 9, and assist in holding the same closed in order to thereby raise the cutting out point and increase the maximum pressure carried in the reservoir. The current for the coil, 3, may be taken from any convenient source, as for instance from a lead, 18, tapped from the line, and the strength of this current and the corresponding` magnetic pull in coil, 3, may be controlled by a resistance, R, inserted in this circuit, 14. This circuit may also be provided with contact terminals, 10, adapted to be connected by a bar, 11, carried on the switch arm, 9, when in closed position, and disconnected in the open position in order not to affect the cutting in point ot the governor.

Any suitable or preferred form of switch mechanism operated automatically by the weight of the load on the car may be employed for varying the resistance in circuit, 14, and thereby regulate the governor, and for this purpose Vwe have indicated a switch arm, 15, ulcrumed at 1G to some fixed part of the car or truck, such as transom, 19, and connected at one end, 17, to a depressible part, such as the bolster, 18, supported on the car springs. `When the car is empty, the arm, 15, occupies the position shown in which all et the resistance, R, is included in the circuit, 1a, so that there is little or no current passing through the coil, 3, and consequently there is no additional magnetic pull or eiiect upon the governor, which then operates in the usual way to cut out the pump at desired maximum degree of pressure for which the governor is adjusted. When, however, the load is increased upon the car, the car springs are further depressed and the switch arm, 15, swings over the contact points to a position in which a certain amount of resistance is cut out, thereby increasing the current in circuit, 14:, and the strength ot the magnetic pull eX- erted by the coil, 3. rlhis operates to raise the cutting out point of the governor and increases the maximum pressure stored in the reservoir.

While we have shown our improvement applied in connection with a particular form ot pump governor, it will be evident that it is not restricted to this form, but may also be employed with any other suitable or preferred governor construction.

lt will now be apparent that by means of our improvement, the maximum degree of air pressure in the reservoir will be regulated according to the weight of the load on the car, increasing as the load increases, and

vdiminishing as the load is reduced, thereby affording at all times a suitable and adequate braking pressure for controlling the ear in an eiiicient and satisfactory manner.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is:

1. The combination on a car, of a pump and reservoir for storing air under pressure, and a pump governor controlled by the weight of the load on the car.

2. The combination on a car, of a pump governor for controlling the degree of fluid pressure stored for braking purposes, and means controlled by the weight of the load on the car for regulating the governor to vary the maximum degree of pressure stored.

3. ln a governing device for Huid pressure pumps, the combination with a switch for controlling the supply of current to the pump, ot a piston subject to the iluid pressure for operating said switch, and means cont-rolled by the weight of the load on the ear for opposing the action of the iiuid pressure on the piston.

4:. ln a governing device for Huid pressure pumps, the combination with a switch operated by the opposing pressures of the compressed luid and an adjustable spring, and means controlled by the weight of the load on the car for assisting the spring in holding the switch closed.

5. ln a governing device for `fluid pressure pumps, the combination with a switch governed by the fluid pressure for controlling the action of the pump, a magnet `coil tending to hold said switch closed, and

means controlled by the weight of the load on the car for varying the current in said magnet.

6. In a governing device for fluid pressure pumps, the combination with a lswitch governed by the fluid pressure for controlling the action of the pump, a magnet coil tending to hold said switch closed, and means controlled by the weight of the load on the car for varying the resistance in the circuit of said magnet. Y

7. ln a governing device for fluid pressure pumps, the combination of a switch for controlling the action of the pump, a piston subject to the opposing pressures of the pump and an adjustable spring for operating the switch, a magnet coil tending to assist the spring in holding the switch closed,

mechanism controlled by the weight Vet theV subject to the opposing pressures of the pump and an adjustable spring for operat- In testimony whereof we have hereunto ing the switch, a magnet coil included in the set our hands. pump circuit and tending to hold the switch JAMES S DOYLE closed, another magnet coil also tending to hold the switch closed, and mechanism controlled by the Weight of the load on the car Witnesses:

for varying the strength of the latter mab- GEO. KEEGAN, net. v H. M. Norms.

FRANK HEDLEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

